SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87f488d94076b6f92a5e365c2191f2fb80393b400853db58a20e5482fa15143d' 
  AND token = 'T1YIgUXhzjUP5sefAqrmTm1RiJtzCwm9Nh+jhRtRGHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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