SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89dd89ca38231bb3a5bcf58c8726ba6b263a46a27ec167d56f1739142329df61' 
  AND token = 'XKWcRPRJTFg5bBqa9nevHE5tzMtl4znCOxBuC2YnU3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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