SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81644cc1e4c715065c4f31b89fd7c9b8f273d778fe34761869db1a9b39b00b1d' 
  AND token = '2Om3egY1kFFkwx8hQT0IaS3OU6x8B+5RCheiugtwYNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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