SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2e51c1f2b163b07e7ad05dc9ade2660a5bee943f578b330d99b65de84ad709f' 
  AND token = 'D1r4Gzjn+zlLe4U9Xuc3GfeJLdmofs7UPovrVeVlnc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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