SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a11a392e2f341bd75b326e2a619e367e9166f243a98b45ba1c52bb22ad7ed40a' 
  AND token = 'npKWpILEpcgNg0Z+CxsWJpTCt166h9aMiWK/m5Xs+Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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