SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84856467455e6fe93960b862018cf745100dfe7e2d417315bef47a980349fcb7' 
  AND token = 'sLgawJBXN4Ag+8zDEpDPwgQLc6xu1iAN/Vx5cVN1ylo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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