SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '629db7a7a247af3b88b975abe8ee02ba966b0a3719f3bfb1137e95a95e91c47d' 
  AND token = 'n0hJWO8Zkmilpg2O1oVufQJWRTIvHt3gatEJm08gF/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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