SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3b3e82236db8fedc800ac53952cfade1488b1ceda4ec6d750bf08c9b4f7c65' 
  AND token = 'LLYwjpsquRuAkUOHFMKerMlBrFOfgTR0ZF/M4uv2zxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}