SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09be7df9eb4e8ddd6e02579699484a9edd079c251a252a546c67f7fd41aeb695' 
  AND token = 'n8/bQZXyk8N70iqFXySDV+/6iKcqw8wJd3Os542gy5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}