SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42cf2889ffdb006109dc4ba0e5308a58cea2016052136cb8cfe4726685cccf16' 
  AND token = 'qI6NGlfvLtLnv3D8TUPFhGB258BqREQR3PWHLjBVXIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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