SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd8051087794b60bfdace5254262b1fd60e51d8a52419633fc2542dbade8696e' 
  AND token = 'pBiD2rqc8KHzBuOWV9SjKJlIIupwD02RBKMM46ZqEg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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