SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32f6e5413d8b7417050d98cfb0bff0deed630aa3841a84d2cb9a1b5809d3cb63' 
  AND token = 'ZdtDnPECEf/Qo8u980QskY3if52tKBvEdc9jMSFw4Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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