SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9977e1495b29b05bfdc310ca4edf23f027e5b9b4c3569fd458cedaf659a967e3' 
  AND token = 'GISVqAsHoqdhz9322TZK0ZhQbIJGyWuW7X68SMuB3xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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