SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fa9525cb458e43d508f5fa17d0739a27b2718d1c642fcc2e6e8192b22b48ea8' 
  AND token = '1B6dqz3p0CxGv8qOOjKAg6BMHDcKr9xQAxUmW3IiB/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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