SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36b66a1766923bf216b073450cdc6d76e1d434c53feb36d312ad919bd25dd29d' 
  AND token = 'hgJwkzGHgLy3VkgfPwwBXPIDZdxMshGY0VuRgEYrpLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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