SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ac03b471a2925edfc0088aa9047150880de386a1dcf7158253e4f2002d71a3a' 
  AND token = '4qsM2TAarGqw0Y3MVc6he5cs+o3m9dMjifSEWPC82QE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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