SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12302a60b565d84e4c6f786524ddcad98fa552c867afd3c924539c4f16b56c17' 
  AND token = 'VfwATPUVIMqvkvepGc7hmkwduASxzxu2YLrhePbNJhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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