SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b78784c2def2784613f433fe09a5a0b5afcccb6a2eec685b10eb1b90f8f5335a' 
  AND token = 'QOn5m6+rOF9kdZc16lJqZqPXYMbESnt8UhPPEhiXGC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00082

JSON explain

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