SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '747618560433332597e812c6d46077315eb57edfa47bc32e7654e56421cb5411' 
  AND token = 'vpKc78wy/nfYgTxppx9RpJiKOgjRXVujydcu/aGLw+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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