SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e7496b8f568e66d6a115d0d98d016441b95b880afc0cb764c5fa337a4cc3f91' 
  AND token = 'p4uyUcb9W7JH+GeyTDwknOsnLwBqH259bV1DO4hifyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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