SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b57a86713d6951a8b84ec7538f49c8d99bc744ce01fad09de6cbb4aee79e198e' 
  AND token = 'Ix8f16+2PXaGFmzOB2Pg9wZnQTwJhC/DXl2VzztgwP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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