SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '274d4b5ab86c3b7738dd2758862008947d127b59314a8789d6e14835f3cd64b7' 
  AND token = 'NIvMzuwLY/QO4GZrRSNwOhwAGFEF+3rE1mfkmKrUgFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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