SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26746461974bd14f6bcb74f975d28b939c9f92ff75d4a06db7544d716620d72f' 
  AND token = 'nOMYdMPsuV7UA4osnyBxo0ii5yrlLlfPAWL0Jh5jPBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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