SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfa5f2499f0331f30c5187969fe631d43df0b9c10a31882883f53a136ebf2e93' 
  AND token = 'A0xt1XNm57aYMhABovabrdKM1Bfrc2e1nM3u/d62n9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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