SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5866c7a4e775ff7649d6fccee71f70168cda6711c5c85a0fa9e351598b6c9356' 
  AND token = 'EBaZwDSXFlgc3SHPyJjd+X5QJhx8qXEdddCWnWzNszs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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