SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14b91737711299572e9ba407ce0c93172386e42a03a9a1f039948ed81f4e44ff' 
  AND token = 'RAAm1ObF6A3jytjWgtEENTJPBEEdApd6HXZCjv9g8Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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