SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '611cdeb83d6929dfe83906ef08f2c978ff97f15275ce7dd4b055b5f4d29f1c23' 
  AND token = '6hAAazPCS1Pg/du3omZI3Pg+/SRe/G5SdK3uSyHkcbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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