SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c2dd57957decb788fedbeae299a73000cb17d8e228924c07ef71c70760bb2f3' 
  AND token = 'nvwLk+iYsfvUWrCZbZsF385yyiIjbB9nrEv6CIEEmPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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