SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75bdfb9b0d37414511ee6b1a57d6d4b468f9c94466f362d643f85a6ce0a1795f' 
  AND token = 'EXJWeDl5509toEkhPi17gRoBkQ40SVKRMYoXM6lMsA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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