SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bff94cb240b750670d2a62dc9656cca8d353d552d6b97acc85a2bf2b16db1c1' 
  AND token = 'oOG3jC9VasS+V2ZaqM8uFfJ1ruvg3Sf/Fl6CKdhGK64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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