SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2060bd6730973fcf5cb8760fec0a03fb03a509b2e2c25461ededa7e219859411' 
  AND token = '0TwArBcJo4zjkaglwRL5/nj36ZmjmwrdfxtqIs4xHDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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