SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c04453cb58f6d6846c35add251e8fa52962f6c9a2706784436563dd38e92205' 
  AND token = 'A61v3PPBHZ02xdrteIXI59yoN5opIPl54Gowv9Xg37g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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