SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac8f332d0e7e73f1fa11664ed8636b219900ac7c985b8da092e3b7b4b3571253' 
  AND token = 'm9oPdzONMPJcueuAaZ7a2l/EgVKxA9ywHSgOV2PZ1jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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