SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cbc840ea827e5ff1d27dad2770fe028baf3c0525a98e713b93cb218f092f6e32' 
  AND token = 'goH8IxKz5PiIY6JBShJYxCXO5ulm2/nCdq7mZmrmURA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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