SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30d415ed9ab232b1ab9074aee189155a4800d9f4af2cf35a7c4da153fa5f5518' 
  AND token = '53ZypyctZyq9ZxFGM5W+EPu11pW2Csmd95dmWf3Jwh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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