SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59580146282f276cc2afd76b9a70816aa525dc443229a1456e8fd5ee7c6ded14' 
  AND token = 'pCkA3Yju0Ovxnucfv9McPcmi1vEY39zOtwPMbBArCLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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