SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c8ced89f851b07e201803445242d15c45a0bff26afdd86c9459294d19bfda970' 
  AND token = 'VhY8ZgtcCqCKKVH2P+2p3cDeg39KWoe+VAy7Hc0ACNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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