SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eebe58776d20add23df0b9003b490daab18eb7a88af84a242a043ff7ee85eba2' 
  AND token = 'yZO58oEftWoPo+8b3Ins4gflYvM7aeKxqfYXG2T67sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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