SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa02ab04852846c024906603df6331fc9bd319c3c2fe8abf03f7e305014c2084' 
  AND token = 'Kj9XSItcHLQKB4Ri8786A4gNQrpi2NjcJO/d4AUcjQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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