SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0432d26c867fa57ad9387cd1221677991fa985d063315f36c11979a64e33d0af' 
  AND token = 'sxmOMqbzsi5Cr5nOr8v05hNEAd6FkZyZ0px3aftpICE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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