SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf6ddfe30e85f42bce43140eeb4dc5562da982f3e0dcce85b12f722eb3abd75f' 
  AND token = 'lufVTSXZ0tCrqAgr4dwOSxNu7swu/lCNVImocL6OkNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}