SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f523fdfb922dc630e2e1dbf2e1a04a5be29613e4b75ecd001a2ec8cb830100b' 
  AND token = 'eY1a0eB+hIZs3Ma+5U/vTPLWIjBumqop5KE+FVczgH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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