SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '364f4b4224bf4f78efbc8d48609c3bd42bac12ca93b2738901c5b1ac75191566' 
  AND token = 'mpFowKpPy03MILZAX1G+0wv+AcLrsR8MI+P1+z8ZqDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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