SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae9a3fcf40438c2d993a96f9dbae738891e2decf926c810441067e475fca4c69' 
  AND token = '/ZPBKoVQ4TxRVOm/bBb2kKAwvVn0fVswZegkpSL9Rvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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