SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8deb7b6329da736173b14a978627aaaef056059ec2e4e13b5d14c89d8f642c54' 
  AND token = 'vatjxZ9tprKa8z6u2WBRMX0vWUCdkeGkU4XDgDmeMPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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