SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa9c4cb720649c696df3a25b37e3b34a224d383591fb6c69297f8158105e3d7e' 
  AND token = '7apFQivD3YCYuspTXYSXMCmGfKPGBbGCNAn/5+VsvSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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