SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4542e36645ee1a50533b5b846ab0973fc2f8532688832e821105f05f29a33f4d' 
  AND token = 'H7K7v8jnxJLFHbrMdOUXNzBM7lsYSVvSYpkgGB395vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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