SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '651e5696c007822df176b9d3545cbe5d2a0ff7c50158446b357e877f336bbfa9' 
  AND token = 'Y4V9m/64rty2IFWE2u+x43+B0LDqNkzVHJAogCGPTAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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