SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb985ac41ff7845644f5401afa64ef68d0ba1e6049fd96a15e95686358b92db8' 
  AND token = 'zK/ty4vEk8lumKyqD0QvAKHReqsYUMCgmW7Uaaud/fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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