SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c0d9d1332b667d84bd0952acdfd811f6a71c75d5e3ebaad60a21ddc804b0f9' 
  AND token = 'Yyvru9Poc0nAd3ahrwCZgcmHpyEqP6IKD5pOhnmzvCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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