SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5b0cf9b14a632a1b9368170f84870e7582aa738ba1ebc87284ce5736719fadb' 
  AND token = '+388tCChFSamovVPA9a2jgBOhuBQM8sKDCNM1lU0qqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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