SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0802331b4eb462ebfb6357d03c9d9411e06a85b1f6bf9261bc4378ae9fac1699' 
  AND token = 'Gi3I67UZzCDzMB2FJ4YzpjErMGKyXUGC+dVM8RFmNUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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