SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69e9e4131e4989efaa7f3aded4c906fc5aa5f5256320e6315124253c58ddb37b' 
  AND token = 'MRScPCI8OmdDNh/UzDoYSCpV1usfWtq9S/jjfdKYeoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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