SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b1070e6f364541dbf56fee51d3a94e1cb26418b22319b6ea706f70b55cb0975' 
  AND token = 'e8wIGu5wyzDXY6fWgmZ+TjbAZvO5Bpb+bqVUgBtPZzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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