SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d99d643cde61ca9647882ec5fea074e70353b8997fa594f48569b564a6f6307' 
  AND token = 'jnPUShyTxHl5yA/pDSL4g+8vazMUqK1Yb7YOadvtlyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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