SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67258d7dd4247669d91d44bc556cd7021260c1103f3385f811a125fbf3e4e979' 
  AND token = 'zGBW10jkSkpZR9nnf37J26gwj8TAWDivD+TEine41Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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