SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87c30ea0a77a95d2ad6fd302642593b863268b28212c59f9c7f4809613d1dc8b' 
  AND token = 'WfzDduUDLWoBK5fTuay4I934ScR89dg3zeCaq7HFhCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}