SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab1b96d42d88ce4439fac78497092c8069299404fdc76d3b72910c7d9977fb97' 
  AND token = 'QwqYarsDB/y5NTLJ+Kn8YasMfJ+memO/hozZpTGFmBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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