SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ab8741f853dc7ac773bbaff4d7bba4e8a75c99dfae6580ef0ccdc8632977292' 
  AND token = 'b8Y2slvIKhI9/CCSox4XIkXs3BOLqb/c1usfU6qvUVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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