SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '862167782aa47ffdbe1ddcf51dc15407db455cb2c1f96e9ffa7f88a392537f77' 
  AND token = 'Mu8/kvSOxhinilCKhtNEWakMdp9ICQv9EyVXsnPOOVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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